6 Infraclavicular Block
Traditional Block Technique
Placement
Anatomy
At the level of the proximal axilla, where infraclavicular block is performed, the axilla is a pyramid-shaped space with an apex, a base, and four sides (Fig. 6-1A). The base is the concave armpit, and the anterior wall is composed of the pectoralis major and minor muscles and their accompanying fasciae. The posterior wall of the axilla is formed by the scapula and the scapular musculature, the subscapularis and the teres major. The latissimus dorsi muscle abuts the teres major muscle to form the inferior aspect of the posterior wall of the axilla (Fig. 6-1B). The medial wall of the axilla is composed of the serratus anterior muscle and its fascia, and the lateral wall is formed by the converging muscle and tendons of the anterior and posterior walls as they insert into the humerus (see Fig. 6-1B). The apex of the axilla is triangular and is formed by the convergence of the clavicle, the scapula, and the first rib. The neurovascular structures of the limb pass into the pyramid-shaped axilla through its apex (Fig. 6-2A).